Family of five-speed dual-clutch transmissions having three planetary gear sets

ABSTRACT

The family of transmissions has a plurality of members that can be utilized in powertrains to provide at least six forward speed ratios and one reverse speed ratio. The transmission family members include three planetary gear sets, two input clutches, nine, ten or eleven torque transmitting mechanisms and a fixed interconnection. The invention provides a low content multi-speed dual clutch transmission mechanism wherein the two input clutches alternately connect the engine to realize odd and even number speed ratio ranges. The torque transmitting mechanisms provide connections between various gear members, the fixed interconnection, the input clutches, the output shaft, and the transmission housing, and are operated in combinations of at least three to establish at least five forward speed ratios and at least one reverse speed ratio.

This is a divisional of application Ser. No. 10/323,072 filed on Dec.18, 2002 now U.S. Pat. No. 6,783,477.

TECHNICAL FIELD

The present invention relates to a family of power transmissions havingtwo input clutches which selectively connect an input shaft to anarrangement of three planetary gear sets to provide at least fiveforward speed ratios and one reverse speed ratio.

BACKGROUND OF THE INVENTION

Passenger vehicles include a powertrain that is comprised of an engine,multi-speed transmission, and a differential or final drive. Themulti-speed transmission increases the overall operating range of thevehicle by permitting the engine to operate through its torque range anumber of times.

A primary focus of transmission and engine design work is in the area ofincreasing vehicle fuel efficiency. Manual transmissions typicallyprovide improved vehicle fuel economy over automatic transmissionsbecause automatic transmissions use a torque converter for vehiclelaunch and multiple plate hydraulically-applied clutches for gearengagement. Clutches of this type, left unengaged or idling, impose aparasitic drag torque on a drive line due to the viscous shearing actionwhich exists between the plates and discs rotating at different speedsrelative to one another. This drag torque adversely affects vehicle fueleconomy for automatic transmissions. Also, the hydraulic pump thatgenerates the pressure needed for operating the above-described clutchesfurther reduces fuel efficiency associated with automatic transmissions.Manual transmissions eliminate these problems.

While manual transmissions are not subject to the above described fuelefficiency related problems, manual transmissions typically provide poorshift quality because a significant torque interruption is requiredduring each gear shift as the engine is disengaged from the transmissionby the clutch to allow shafts rotating at different speeds to besynchronized.

So called “automated manual” transmissions provide electronic shiftingin a manual transmission configuration which, in certain circumstances,improves fuel efficiency by eliminating the parasitic losses associatedwith the torque converter and hydraulic pump needed for clutching. Likemanual transmissions, a drawback of automated manual transmissions isthat the shift quality is not as high as an automatic transmissionbecause of the torque interruption during shifting.

So called “dual-clutch automatic” transmissions also eliminate thetorque converter and replace hydraulic clutches with synchronizers butthey go further to provide gear shift quality which is superior to theautomated manual transmission and similar to the conventional automatictransmission, which makes them quite attractive. However, most knowndual-clutch automatic transmissions include a lay shaft or countershaftgear arrangement, and have not been widely applied in vehicles becauseof their complexity, size and cost. For example, a dual clutch lay shafttransmission could require eight sets of gears, two input/shift clutchesand seven synchronizers/dog clutches to provide six forward speed ratiosand a reverse speed ratio. An example of a dual-clutch automatictransmission is described in U.S. Pat. No. 5,385,064, which is herebyincorporated by reference.

SUMMARY OF THE INVENTION

The invention provides a low content multi-speed dual-clutchtransmission family utilizing planetary gear sets rather than lay shaftgear arrangements. In particular, the invention requires only threeplanetary gear sets, two input/shift clutches, and nine or tenselectable torque transmitting mechanisms to provide at least sixforward speed ratios and a reverse speed ratio.

According to one aspect of the invention, the family of transmissionshas three planetary gear sets, each of which includes a first, secondand third member, which members may comprise a sun gear, ring gear, or aplanet carrier assembly member.

In referring to the first, second and third gear sets in thisdescription and in the claims, these sets may be counted “first” to“third” in any order in the drawings (i.e. left-to-right, right-to-left,etc.).

In another aspect of the present invention, each of the planetary gearsets may be of the single pinion type or of the double pinion type.

In yet another aspect of the present invention, a first input clutch anda second input clutch selectively connect the input shaft with othermembers of the transmission.

In another aspect of the invention, first and second torque transmittingmechanisms, such as synchronizers, selectively connect the first memberand the second member of the first planetary gear set, respectively,with the first input clutch.

In another aspect of the invention, third, fourth and fifth torquetransmitting mechanisms, such as synchronizers, selectively connect thefirst, second and third members of the first planetary gear set,respectively, with the first member of the second planetary gear set andthe output shaft.

In yet another aspect of the present invention, the second member of thesecond planetary gear set is continuously connected with the secondinput clutch.

In another aspect of the invention, sixth and seventh torquetransmitting mechanisms, such as synchronizers, selectively connectmembers of the second planetary gear set with members of the thirdplanetary gear set.

In still a further aspect of the invention, eighth and ninth torquetransmitting mechanisms, such as braking synchronizers, selectivelyconnect members of the first planetary gear set with a stationary member(transmission housing).

In still a further aspect of the invention, a tenth torque-transmittingmechanism, such as a braking synchronizer, selectively connects a memberof the third planetary gear set with the stationary member.

In yet another aspect of the present invention, a member of a secondplanetary gear set is continuously connected with a member of the thirdplanetary gear set through a first interconnecting member.

In accordance with a further aspect of the invention, the input clutchesand torque transmitting mechanisms are selectively engaged incombinations of at least three to provide at least five forward speedratios and a reverse speed ratio.

In accordance with a further aspect of the invention, the first inputclutch is applied for odd number speed ranges, and the second inputclutch is applied for even number speed ranges, or vice versa.

In another aspect of the invention, the first input clutch and thesecond input clutch are interchanged (i.e. alternately engaged) to shiftfrom odd number speed range to even number speed range, or vice versa.

In accordance with a further aspect of the invention, each selectedtorque transmitting mechanism for a new speed ratio is engaged prior toshifting of the input clutches to achieve shifts without torqueinterruptions.

In accordance with a further aspect of the invention, at least one pairof synchronizers is executed as a double synchronizer to reduce cost andpackage size.

In accordance with a further aspect of the invention, the first inputclutch is eliminated and the first and second torque transmittingmechanisms are used as input clutches to further reduce content.

The above objects, features, advantages, and other objects, features,and advantages of the present invention are readily apparent from thefollowing detailed description of the best modes for carrying out theinvention when taken in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 a is a schematic representation of a powertrain including aplanetary transmission incorporating a family member of the presentinvention;

FIG. 1 b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 1 a;

FIG. 2 a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

FIG. 2 b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 2 a;

FIG. 3 a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

FIG. 3 b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 3 a;

FIG. 4 a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

FIG. 4 b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 4 a;

FIG. 5 a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

FIG. 5 b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 5 a;

FIG. 6 a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

FIG. 6 b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 6 a;

FIG. 7 a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

FIG. 7 b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 7 a;

FIG. 8 a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

FIG. 8 b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 8 a;

FIG. 9 a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

FIG. 9 b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 9 a;

FIG. 10 a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

FIG. 10 b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 10 a;

FIG. 11 a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

FIG. 11 b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 11 a.

FIG. 12 a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention; and

FIG. 12 b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 12 a.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the drawings, wherein like characters represent the same orcorresponding parts throughout the several views, there is shown in FIG.1 a a powertrain 10 having a conventional engine 12, a planetarytransmission 14, and a conventional final drive mechanism 16.

The planetary transmission 14 includes an input shaft 17 continuouslyconnected with the engine 12, a planetary gear arrangement 18, and anoutput shaft 19 continuously connected with the final drive mechanism16. The planetary gear arrangement 18 includes three planetary gear sets20, 30 and 40.

The planetary gear set 20 includes a sun gear member 22, a ring gearmember 24, and a planet carrier assembly member 26. The planet carrierassembly member 26 includes a plurality of pinion gears 27 rotatablymounted on a carrier member 29 and disposed in meshing relationship withboth the sun gear member 22 and the ring gear member 24.

The planetary gear set 30 includes a sun gear member 32, a ring gearmember 34, and a planet carrier assembly member 36. The planet carrierassembly member 36 includes a plurality of pinion gears 37 rotatablymounted on a carrier member 39 and disposed in meshing relationship withboth the sun gear member 32 and the ring gear member 34.

The planetary gear set 40 includes a sun gear member 42, a ring gearmember 44, and a planet carrier assembly member 46. The planet carrierassembly member 46 includes a plurality of intermeshing pinion gears 47,48 rotatably mounted on a carrier member 49 and disposed in meshingrelationship with the ring gear member 44 and the sun gear member 42,respectively.

As a result of the dual clutch arrangement of the invention, the threeplanetary gear sets 20, 30 and 40 are divided into first and secondtransmission subsets 60, 61 which are alternatively engaged to provideodd number and even number speed ranges, respectively. Transmissionsubset 60 includes planetary gear set 20 and transmission subset 61includes planetary gear sets 30 and 40. The output shaft 19 iscontinuously connected with a member of transmission subset 61.

As mentioned above, the first and second input clutches 62, 63 arealternatively engaged for transmitting power from the input shaft 17 totransmission subset 60 or transmission subset 61. The first and secondinput clutches 62, 63 are controlled electronically, and the disengagedinput clutch is gradually engaged while the engaged input clutch isgradually disengaged to facilitate transfer of power from onetransmission subset to another. In this manner, shift quality ismaintained, as in an automatic transmission, while providing better fueleconomy because no torque converter is required, and hydraulicsassociated with “wet” clutching are eliminated. All gear speeds arepreselected within the transmission subsets 60, 61 prior to engaging therespective input clutches 62, 63. The preselection is achieved by meansof electronically controlled synchronizers. As shown, the planetary geararrangement includes eleven torque transmitting mechanisms 64, 65, 66,67, 68, 69, 70, 71, 72, 73 and 74. The torque transmitting mechanisms64, 65, 71 and 72 comprise braking synchronizers (brakes) which connectgears to the transmission housing 80, and the torque transmittingmechanisms 66, 67, 68, 69, 70, 73 and 74 comprise rotatingsynchronizers.

The braking synchronizers and rotating synchronizers are referred to inthe claims as follows: first and second torque transmitting mechanisms66, 67; third, fourth and fifth torque transmitting mechanisms 68, 69,70; sixth and seventh torque transmitting mechanisms 73, 74; eighth andninth torque transmitting mechanisms 64, 65; and tenth and eleventhtorque transmitting mechanisms 71, 72. Other family members are referredto similarly in the claims (i.e., synchronizers generally from left toright in Figures, and then braking synchronizers generally from left toright in Figures).

By way of example, synchronizers which may be implemented as therotating and/or braking synchronizers referenced herein are shown in thefollowing patents, each of which are incorporated by reference in theirentirety: U.S. Pat. Nos. 5,651,435; 5,975,263; 5,560,461; 5,641,045;5,497,867; 6,354,416.

Accordingly, the input shaft 17 is alternately connected with the firstand second transmission subsets 60, 61 (i.e. through the clutch 62 tothe synchronizers 66 and 67 and through the clutch 63 to the sun gearmember 32). The planet carrier assembly member 36 is continuouslyconnected with the ring gear member 44 through the interconnectingmember 76.

The planet carrier assembly member 26 is selectively connectable withthe transmission housing 80 through the braking synchronizer 64. Thering gear member 24 is selectively connectable with the transmissionhousing 80 through the braking synchronizer 65. The planet carrierassembly member 26 is selectively connectable with the input clutch 62through the synchronizer 66. The sun gear member 22 is selectivelyconnectable with the input clutch 62 through the synchronizer 67. Thering gear member 24 is selectively connectable with the planet carrierassembly member 36 through the synchronizer 68. The planet carrierassembly member 26 is selectively connectable with the planet carrierassembly member 36 through the synchronizer 69. The sun gear member 22is selectively connectable with the planet carrier assembly member 36through the synchronizer 70. The planet carrier assembly member 46 isselectively connectable with the transmission housing 80 through thebraking synchronizer 71. The sun gear member 42 is selectivelyconnectable with the transmission housing 80 through the brakingsynchronizer 72. The ring gear member 34 is selectively connectable withthe planet carrier assembly member 46 through the synchronizer 73. Thering gear member 34 is selectively connectable with the sun gear member42 through the synchronizer 74.

As shown in FIG. 1 b, and in particular the truth table disclosedtherein, the input clutches and torque transmitting mechanisms areselectively engaged in combinations of at least three to provide sixforward speed ratios and a reverse speed ratio.

The reverse speed ratio is established with the engagement of the inputclutch 62, the braking synchronizer 64 and the synchronizers 67, 68. Theinput clutch 62 and the synchronizer 67 connect the sun gear member 22to the input shaft 17. The braking synchronizer 64 connects the planetcarrier assembly member 26 to the transmission housing 80. Thesynchronizer 68 connects the ring gear member 24 to the planet carrierassembly member 36. The sun gear member 22 rotates at the same speed asthe input shaft 17. The planet carrier assembly member 26 does notrotate. The ring gear member 24 and the planet carrier assembly member36 rotate at the same speed as the output shaft 19. The ring gear member24, and therefore the output shaft 19, rotates at a speed determinedfrom the speed of the sun gear member 22 and the ring gear/sun geartooth ratio of the planetary gear set 20. The numerical value of thereverse speed ratio is determined utilizing the ring gear/sun gear toothratio of the planetary gear set 20.

The first forward speed ratio is established with the engagement of theinput clutch 62, the braking synchronizer 65 and the synchronizers 67,69. The input clutch 62 and the synchronizer 67 connect the sun gearmember 22 to the input shaft 17. The braking synchronizer 65 connectsthe ring gear member 24 to the transmission housing 80. The synchronizer69 connects the planet carrier assembly member 26 to the planet carrierassembly member 36. The sun gear member 22 rotates at the same speed asthe input shaft 17. The planet carrier assembly member 26 and the planetcarrier assembly member 36 rotate at the same speed as the output shaft19. The ring gear member 24 does not rotate. The planet carrier assemblymember 26, and therefore the output shaft 19, rotates at a speeddetermined from the speed of the sun gear member 22 and the ringgear/sun gear tooth ratio of the planetary gear set 20. The numericalvalue of the first forward speed ratio is determined utilizing the ringgear/sun gear tooth ratio of the planetary gear set 20.

The second forward speed ratio is established with the engagement of theinput clutch 63, the braking synchronizer 71 and the synchronizer 73.The input clutch 63 connects the sun gear member 32 to the input shaft17. The braking synchronizer 71 connects the planet carrier assemblymember 46 to the transmission housing 80. The synchronizer 73 connectsthe ring gear member 34 to the planet carrier assembly member 46. Thesun gear member 32 rotates at the same speed as the input shaft 17. Theplanet carrier assembly member 36 and the ring gear member 44 rotate atthe same speed as the output shaft 19. The ring gear member 34 and theplanet carrier assembly member 46 do not rotate. The planet carrierassembly member 36, and therefore the output shaft 19, rotates at aspeed determined from the speed of the sun gear member 32 and the ringgear/sun gear tooth ratio of the planetary gear set 30. The numericalvalue of the second forward speed ratio is determined utilizing the ringgear/sun gear tooth ratio of the planetary gear set 30.

The third forward speed ratio is established with the engagement of theinput clutch 62, the braking synchronizer 64 and the synchronizers 67,70. In this configuration, the input shaft 17 is directly connected tothe output shaft 19. The numerical value of the third forward speedratio is 1.

The fourth forward speed ratio is established with the engagement of theinput clutch 63, the braking synchronizer 71 and the synchronizer 74.The input clutch 63 connects the sun gear member 32 to the input shaft17. The braking synchronizer 71 connects the planet carrier assemblymember 46 to the transmission housing 80. The synchronizer 74 connectsthe ring gear member 34 to the sun gear member 42. The sun gear member32 rotates at the same speed as the input shaft 17. The planet carrierassembly member 36 and the ring gear member 44 rotate at the same speedas the output shaft 19. The ring gear member 34 rotates at the samespeed as the sun gear member 42. The planet carrier assembly member 36,and therefore the output shaft 19, rotates at a speed determined fromthe speed of the ring gear member 34, the speed of the sun gear member32 and the ring gear/sun gear tooth ratio of the planetary gear set 30.The planet carrier assembly member 46 does not rotate. The ring gearmember 44 rotates at a speed determined from the speed of the sun gearmember 42 and the ring gear/sun gear tooth ratio of the planetary gearset 40. The numerical value of the fourth forward speed ratio isdetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear set 30, 40.

The fifth forward speed ratio is established with the engagement of theinput clutch 62, the braking synchronizer 65 and the synchronizers 66,70. The input clutch 62 and the synchronizer 66 connect the planetcarrier assembly member 26 to the input shaft 17. The brakingsynchronizer 65 connects the ring gear member 24 to the transmissionhousing 80. The synchronizer 70 connects the sun gear member 22 to theplanet carrier assembly member 36. The sun gear member 22 and the planetcarrier assembly member 36 rotate at the same speed as the output shaft19. The planet carrier assembly member 26 rotates at the same speed asthe input shaft 17. The ring gear member 24 does not rotate. The sungear member 22, and therefore the output shaft 19, rotates at a speeddetermined from the speed of the planet carrier assembly member 26 andthe ring gear/sun gear tooth ratio of the planetary gear set 20. Thenumerical value of the fifth forward speed ratio is determined utilizingthe ring gear/sun gear tooth ratio of the planetary gear set 20.

The sixth forward speed ratio is established with the engagement of theinput clutch 63, the braking synchronizer 72 and the synchronizer 73.The input clutch 63 connects the sun gear member 32 to the input shaft17. The braking synchronizer 72 connects the sun gear member 42 to thetransmission housing 80. The synchronizer 73 connects the ring gearmember 34 to the planet carrier assembly member 46. The sun gear member32 rotates at the same speed as the input shaft 17. The planet carrierassembly member 36 and the ring gear member 44 rotate at the same speedas the output shaft 19. The ring gear member 34 rotates at the samespeed as the planet carrier assembly member 46. The planet carrierassembly member 36, and therefore the output shaft 19, rotates at aspeed determined from the speed of the ring gear member 34, the speed ofthe sun gear member 32 and the ring gear/sun gear tooth ratio of theplanetary gear set 30. The sun gear member 42 does not rotate. The ringgear member 44 rotates at a speed determined from the speed of theplanet carrier assembly member 46 and the ring gear/sun gear tooth ratioof the planetary gear set 40. The numerical value of the sixth forwardspeed ratio is determined utilizing the ring gear/sun gear tooth ratiosof the planetary gear sets 30, 40.

As set forth above, the engagement schedule for the torque transmittingmechanisms is shown in the truth table of FIG. 1 b. This truth tablealso provides an example of speed ratios that are available utilizingthe ring gear/sun gear tooth ratios given by way of example in FIG. 1 b.The R1/S1 value is the tooth ratio of the planetary gear set 20; theR2/S2 value is the tooth ratio of the planetary gear set 30; and theR3/S3 value is the tooth ratio of the planetary gear set 40. Also, thechart of FIG. 1 b describes the ratio steps that are attained utilizingthe sample of tooth ratios given. For example, the step ratio betweenfirst and second forward speed ratios is 1.68, while the step ratiobetween the reverse and first forward ratio is −0.60.

FIG. 2 a shows a powertrain 110 having a conventional engine 12, aplanetary transmission 114, and a conventional final drive mechanism 16.The planetary transmission 114 includes an input shaft 17 connected withthe engine 12, a planetary gear arrangement 118, and an output shaft 19connected with the final drive mechanism 16. The planetary geararrangement 118 includes three planetary gear sets 120, 130 and 140.

The planetary gear set 120 includes a sun gear member 122, a ring gearmember 124, and a planet carrier assembly member 126. The planet carrierassembly member 126 includes a plurality of pinion gears 127 rotatablymounted on a carrier member 129 and disposed in meshing relationshipwith both the sun gear member 122 and the ring gear member 124.

The planetary gear set 130 includes a sun gear member 132, a ring gearmember 134, and a planet carrier assembly member 136. The planet carrierassembly member 136 includes a plurality of intermeshing pinion gears137, 138 rotatably mounted on a carrier member 139 and disposed inmeshing relationship with the ring gear member 134 and the sun gearmember 132, respectively.

The planetary gear set 140 includes a sun gear member 142, a ring gearmember 144, and a planet carrier assembly member 146. The planet carrierassembly member 146 includes a plurality of intermeshing pinion gears147, 148 rotatably mounted on a carrier member 149 and disposed inmeshing relationship with the ring gear member 144 and the sun gearmember 142, respectively.

As a result of the dual clutch arrangement of the invention, the threeplanetary gear sets 120, 130 and 140 are divided into first and secondtransmission subsets 160, 161 which are alternatively engaged to provideodd number and even number speed ranges, respectively. Transmissionsubset 160 includes planetary gear set 120 and transmission subset 161includes planetary gear sets 130 and 140. The output shaft 19 iscontinuously connected with a member of transmission subset 161.

As mentioned above, the first and second input clutches 162, 163 arealternatively engaged for transmitting power from the input shaft 17 totransmission subset 160 or transmission subset 161. The first and secondinput clutches 162, 163 are controlled electronically, and thedisengaged input clutch is gradually engaged while the engaged inputclutch is gradually disengaged to facilitate transfer of power from onetransmission subset to another. In this manner, shift quality ismaintained, as in an automatic transmission, while providing better fueleconomy because no torque converter is required, and hydraulicsassociated with “wet” clutching are eliminated. All gear speeds arepreselected within the transmission subsets 160, 161 prior to engagingthe respective input clutches 162, 163. The preselection is achieved bymeans of electronically controlled synchronizers. As shown, theplanetary gear arrangement includes eleven torque transmittingmechanisms 164, 165, 166, 167, 168, 169, 170, 171, 172, 173 and 174. Thetorque transmitting mechanisms 164, 165, 171 and 172 comprise brakingsynchronizers (brakes) which connect gears to the transmission housing180, and the torque transmitting mechanisms 166, 167, 168, 169,170, 173and 174 comprise rotating synchronizers.

Accordingly, the input shaft 17 is alternately connected with the firstand second transmission subsets 160, 161 (i.e. through the clutch 162 tothe synchronizers 166 and 167 and through the clutch 163 to the ringgear member 134). The sun gear member 132 is continuously connected withthe sun gear member 142 through the interconnecting member 176.

The planet carrier assembly member 126 is selectively connectable withthe transmission housing 180 through the braking synchronizer 164. Thering gear member 124 is selectively connectable with the transmissionhousing 180 through the braking synchronizer 165. The planet carrierassembly member 126 is selectively connectable with the input shaft 17through the clutch 162 and the synchronizer 166. The sun gear member 122is selectively connectable with the input shaft 17 through the clutch162 and the synchronizer 167. The ring gear member 124 is selectivelyconnectable with the planet carrier assembly member 136 through thesynchronizer 168. The planet carrier assembly member 126 is selectivelyconnectable with the planet carrier assembly member 136 through thesynchronizer 169. The sun gear member 122 is selectively connectablewith the planet carrier assembly member 136 through the synchronizer170. The ring gear member 144 is selectively connectable with thetransmission housing 180 through the braking synchronizer 171. Theplanet carrier assembly member 146 is selectively connectable with thetransmission housing 180 through the braking synchronizer 172. Theplanet carrier assembly member 136 is selectively connectable with thering gear member 144 through the synchronizer 173. The planet carrierassembly member 136 is selectively connectable with the planet carrierassembly member 146 through the synchronizer 174.

As shown in FIG. 2 b, and in particular the truth table disclosedtherein, the input clutches and torque transmitting mechanisms areselectively engaged in combinations of at least three to provide sixforward speed ratios and a reverse speed ratio.

The reverse speed ratio is established with the engagement of the inputclutch 162, the braking synchronizer 164 and the synchronizers 167, 168.The input clutch 162 and the synchronizer 167 connect the sun gearmember 122 to the input shaft 17. The braking synchronizer 164 connectsthe planet carrier assembly member 126 to the transmission housing 180.The synchronizer 168 connects the ring gear member 124 to the planetcarrier assembly member 136. The sun gear member 122 rotates at the samespeed as the input shaft 17. The planet carrier assembly member 126 doesnot rotate. The ring gear member 124 and the planet carrier assemblymember 136 rotate at the same speed as the output shaft 19. The ringgear member 124, and therefore the output shaft 19, rotates at a speeddetermined from the speed of the sun gear member 122 and the ringgear/sun gear tooth ratio of the planetary gear set 120. The numericalvalue of the reverse speed ratio is determined utilizing the ringgear/sun gear tooth ratio of the planetary gear set 120.

The first forward speed ratio is established with the engagement of theinput clutch 162, the braking synchronizer 165 and the synchronizers167, 169. The input clutch 162 and the synchronizer 167 connect the sungear member 122 to the input shaft 17. The braking synchronizer 165connects the ring gear member 124 to the transmission housing 180. Thesynchronizer 169 connects the planet carrier assembly member 126 to theplanet carrier assembly member 136. The sun gear member 122 rotates atthe same speed as the input shaft 17. The planet carrier assembly member126 and the planet carrier assembly member 136 rotate at the same speedas the output shaft 19. The ring gear member 124 does not rotate. Theplanet carrier assembly member 126, and therefore the output shaft 19,rotates at a speed determined from the speed of the sun gear member 122and the ring gear/sun gear tooth ratio of the planetary gear set 120.The numerical value of the first forward speed ratio is determinedutilizing the ring gear/sun gear tooth ratio of the planetary gear set120.

The second forward speed ratio is established with the engagement of theinput clutch 163, the braking synchronizer 172 and the synchronizer 173.The input clutch 163 connects the ring gear member 134 to the inputshaft 17. The braking synchronizer 172 connects the planet carrierassembly member 146 to the transmission housing 180. The synchronizer173 connects the ring gear member 144 to the planet carrier assemblymember 136. The sun gear member 132 rotates at the same speed as the sungear member 142. The planet carrier assembly member 136 and the ringgear member 144 rotate at the same speed as the output shaft 19. Thering gear member 134 rotates at the same speed as the input shaft 17.The planet carrier assembly member 136, and therefore the output shaft19, rotates at a speed determined from the speed of the ring gear member134, the speed of the sun gear member 132 and the ring gear/sun geartooth ratio of the planetary gear set 130. The planet carrier assemblymember 146 does not rotate. The ring gear member 144 rotates at a speeddetermined from the speed of the sun gear member 142 and the ringgear/sun gear tooth ratio of the planetary gear set 140. The numericalvalue of the second forward speed ratio is determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 130, 140.

The third forward speed ratio is established with the engagement of theinput clutch 162, the braking synchronizer 164 and the synchronizers167, 170. In this configuration, the input shaft 17 is directlyconnected to the output shaft 19. The numerical value of the thirdforward speed ratio is 1.

The fourth forward speed ratio is established with the engagement of theinput clutch 163, and the braking synchronizers 171, 172. The inputclutch 163 connects the ring gear member 134 to the input shaft 17. Thebraking synchronizer 171 connects the ring gear member 144 to thetransmission housing 180. The braking synchronizer 172 connects theplanet carrier assembly member 146 to the transmission housing 180. Thesun gear member 132 and the planetary gear set 140 do not rotate. Theplanet carrier assembly member 136 rotates at the same speed as theoutput shaft 19. The ring gear member 134 rotates at the same speed asthe input shaft 17. The planet carrier assembly member 136, andtherefore the output shaft 19, rotates at a speed determined from thespeed of the ring gear member 134 and the ring gear/sun gear tooth ratioof the planetary gear set 130. The numerical value of the fourth forwardspeed ratio is determined utilizing the ring gear/sun gear tooth ratioof the planetary gear set 130.

The fifth forward speed ratio is established with the engagement of theinput clutch 162, the braking synchronizer 165, and the synchronizers166, 170. The input clutch 162 and the synchronizer 166 connect theplanet carrier assembly member 126 to the input shaft 17. The brakingsynchronizer 165 connects the ring gear member 124 to the transmissionhousing 180. The synchronizer 170 connects the sun gear member 122 tothe planet carrier assembly member 136. The sun gear member 122 and theplanet carrier assembly member 136 rotate at the same speed as theoutput shaft 19. The planet carrier assembly member 126 rotates at thesame speed as the input shaft 17. The ring gear member 124 does notrotate. The sun gear member 122, and therefore the output shaft 19,rotates at a speed determined from the speed of the planet carrierassembly member 126 and the ring gear/sun gear tooth ratio of theplanetary gear set 120. The numerical value of the fifth forward speedratio is determined utilizing the ring gear/sun gear tooth ratio of theplanetary gear set 120.

The sixth forward speed ratio is established with the engagement of theinput clutch 163, the braking synchronizer 171 and the synchronizer 174.The input clutch 163 connects the ring gear member 134 to the inputshaft 17. The braking synchronizer 171 connects the ring gear member 144to the transmission housing 180. The synchronizer 174 connects theplanet carrier assembly member 136 to the planet carrier assembly member146. The sun gear member 132 rotates at the same speed as the sun gearmember 142. The planet carrier assembly member 136 and the planetcarrier assembly member 146 rotate at the same speed as the output shaft19. The ring gear member 134 rotates at the same speed as the inputshaft 17. The planet carrier assembly member 136, and therefore theoutput shaft 19, rotates at a speed determined from the speed of thering gear member 134, the speed of the sun gear member 132 and the ringgear/sun gear tooth ratio of the planetary gear set 130. The ring gearmember 144 does not rotate. The planet carrier assembly member 146rotates at a speed determined from the speed of the sun gear member 142and the ring gear/sun gear tooth ratio of the planetary gear set 140.The numerical value of the sixth forward speed ratio is determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets130, 140.

As set forth above, the truth table of FIG. 2 b describes the engagementsequence of the torque transmitting mechanisms utilized to provide areverse drive ratio and six forward speed ratios. The truth table alsoprovides an example of the ratios that can be attained with the familymembers shown in FIG. 2 a utilizing the sample tooth ratios given inFIG. 2 b. The R1/S1 value is the tooth ratio of the planetary gear set120; the R2/S2 value is the tooth ratio of the planetary gear set 130;and the R3/S3 value is the tooth ratio of the planetary gear set 140.Also shown in FIG. 2 b are the ratio steps between single step ratios inthe forward direction as well as the reverse to first ratio step. Forexample, the first to second step ratio is 1.85.

Turning the FIG. 3 a, a powertrain 210 having a conventional engine 12,a planetary transmission 214, and conventional final drive mechanism 16is shown.

The planetary transmission 214 includes an input shaft 17 continuouslyconnected with the engine 12, a planetary gear arrangement 218, and anoutput shaft 19 continuously connected with the final drive mechanism16. The planetary gear arrangement 218 includes three planetary gearsets 220, 230 and 240.

The planetary gear set 220 includes a sun gear member 222, a ring gearmember 224, and a planet carrier assembly member 226. The planet carrierassembly member 226 includes a plurality of pinion gears 227 rotatablymounted on a carrier member 229 and disposed in meshing relationshipwith both the sun gear member 222 and the ring gear member 224.

The planetary gear set 230 includes a sun gear member 232, a ring gearmember 234, and a planet carrier assembly member 236. The planet carrierassembly member 236 includes a plurality of intermeshing pinion gears237, 238 rotatably mounted on a carrier member 239 and disposed inmeshing relationship with the ring gear member 234 and the sun gearmember 232, respectively.

The planetary gear set 240 includes a sun gear member 242, a ring gearmember 244, and a planet carrier assembly member 246. The planet carrierassembly member 246 includes a plurality of intermeshing pinion gears247, 248 rotatably mounted on a carrier member 249 and disposed inmeshing relationship with the ring gear member 244 and the sun gearmember 242, respectively.

As a result of the dual clutch arrangement of the invention, the threeplanetary gear sets 220, 230 and 240 are divided into first and secondtransmission subsets 260, 261 which are alternatively engaged to provideodd number and even number speed ranges, respectively. Transmissionsubset 260 includes planetary gear set 220, and transmission subset 261includes planetary gear sets 230 and 240. The output shaft 19 iscontinuously connected with a member of transmission subset 261.

As mentioned above, the first and second input clutches 262, 263 arealternatively engaged for transmitting power from the input shaft 17 totransmission subset 260 or transmission subset 261. The first and secondinput clutches 262, 263 are controlled electronically, and thedisengaged input clutch is gradually engaged while the engaged inputclutch is gradually disengaged to facilitate transfer of power from onetransmission subset to another. In this manner, shift quality ismaintained, as in an automatic transmission, while providing better fueleconomy because no torque converter is required, and hydraulicsassociated with “wet” clutching are eliminated. All gear speeds arepreselected within the transmission subsets 260, 261 prior to engagingthe respective input clutches 262, 263. The preselection is achieved bymeans of electronically controlled synchronizers. As shown, theplanetary gear arrangement includes eleven torque transmittingmechanisms 264, 265, 266, 267, 268, 269, 270, 271, 272, 273 and 274. Thetorque transmitting mechanisms 264, 265, 271 and 272 comprise brakingsynchronizers (brakes) which connect gears to the transmission housing280, and the torque transmitting mechanisms 266, 267, 268, 269, 270, 273and 274 comprise rotating synchronizers.

Accordingly, the input shaft 17 is alternately connected with the firstand second transmission subsets 260, 261 (i.e. through the clutch 262 tothe synchronizers 266 and 267 and through the clutch 263 to the ringgear member 234). The sun gear member 232 is continuously connected withthe planet carrier assembly member 246 through the interconnectingmember 276.

The planet carrier assembly member 226 is selectively connectable withthe transmission housing 280 through the braking synchronizer 264. Thering gear member 224 is selectively connectable with the transmissionhousing 280 through the braking synchronizer 265. The planet carrierassembly member 226 is selectively connectable with the input shaft 17through the input clutch 262 and the synchronizer 266. The sun gearmember 222 is selectively connectable with the input shaft 17 throughthe synchronizer 267 and the input clutch 262. The ring gear member 224is selectively connectable with the planet carrier assembly member 236through the synchronizer 268. The planet carrier assembly member 226 isselectively connectable with the planet carrier assembly member 236through the synchronizer 269. The sun gear member 222 is selectivelyconnectable with the planet carrier assembly member 236 through thesynchronizer 270. The ring gear member 244 is selectively connectablewith the transmission housing 280 through the braking synchronizer 271.The sun gear member 242 is selectively connectable with the transmissionhousing 280 through the braking synchronizer 272. The planet carrierassembly member 236 is selectively connectable with the ring gear member244 through the synchronizer 273. The planet carrier assembly member 236is selectively connectable with the sun gear member 242 through thesynchronizer 274.

As shown in FIG. 3 b, and in particular the truth table disclosedtherein, the input clutches and torque transmitting mechanisms areselectively engaged in combinations of at least three to provide sixforward speed ratio and a reverse speed ratio.

The reverse speed ratio is established with the engagement of the inputclutch 262, the braking synchronizer 264 and the synchronizer 267, 268.The input clutch 262 and the synchronizer 267 connect the sun gearmember 222 to the input shaft 17. The braking synchronizer 264 connectsthe planet carrier assembly member 226 to the transmission housing 280.The synchronizer 268 connects the ring gear member 224 to the planetcarrier assembly member 236. The sun gear member 222 rotates at the samespeed as the input shaft 17. The planet carrier assembly member 226 doesnot rotate. The ring gear member 224 and the planet carrier assemblymember 236 rotate at the same speed as the output shaft 19. The ringgear member 224, and therefore the output shaft 19, rotates at a speeddetermined from the speed of the sun gear member 222 and the ringgear/sun gear tooth ratio of the planetary gear set 220. The numericalvalue of the reverse speed ratio is determined utilizing the ringgear/sun gear tooth ratio of the planetary gear set 220.

The first forward speed ratio is established with the engagement of theinput clutch 262, the braking synchronizer 265 and the synchronizer 267,269. The input clutch 262 and the synchronizer 267 connect the sun gearmember 222 to the input shaft 17. The braking synchronizer 265 connectsthe ring gear member 224 to the transmission housing 280. Thesynchronizer 269 connects the planet carrier assembly member 226 to theplanet carrier assembly member 236. The sun gear member 222 rotates atthe same speed as the input shaft 17. The planet carrier assembly member226 and the planet carrier assembly member 236 rotate at the same speedas the output shaft 19. The ring gear member 224 does not rotate. Thesun gear member 226, and therefore the output shaft 19, rotates at aspeed determined from the speed of the sun gear member 222 and the ringgear/sun gear tooth ratio of the planetary gear set 220. The numericalvalue of the first forward speed ratio is determined utilizing the ringgear/sun gear tooth ratio of the planetary gear set 220.

The second forward speed ratio is established with the engagement of theinput clutch 263, the braking synchronizer 272 and the synchronizer 273.The input clutch 263 connects the ring gear member 234 to the inputshaft 17. The braking synchronizer 272 connects the sun gear member 242to the transmission housing 280. The synchronizer 273 connects theplanet carrier assembly member 236 to the ring gear member 244. The sungear member 232 rotates at the same speed as the planet carrier assemblymember 246. The planet carrier assembly member 236 and the ring gearmember 244 rotate at the same speed as the output shaft 19. The ringgear member 234 rotates at the same speed as the input shaft 17. Theplanet carrier assembly member 236, and therefore the output shaft 19,rotates at a speed determined from the speed of the ring gear member234, the speed of the sun gear member 232 and the ring gear/sun geartooth ratio of the planetary gear set 230. The sun gear member 242 doesnot rotate. The ring gear member 244 rotates at a speed determined fromthe speed of the planet carrier assembly member 246 and the ringgear/sun gear tooth ratio of the planetary gear set 240. The numericalvalue of the second forward speed ratio is determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 230, 240.

The third forward speed ratio is established with the engagement of theinput clutch 262, the braking synchronizer 264 and the synchronizer 267,270. In this configuration, the input shaft 17 is directly connected tothe output shaft 19. The numerical value of the third forward speedratio is 1.

The fourth forward speed ratio is established with the engagement of theinput clutch 263 and the braking synchronizers 271, 272. The inputclutch 263 connects the ring gear member 234 to the input shaft 17. Thebraking synchronizer 271 connects the ring gear member 244 to thetransmission housing 280. The braking synchronizer 272 connects the sungear member 242 to the transmission housing 280. The sun gear member 232and the planetary gear set 240 do not rotate. The planet carrierassembly member 236 rotates at the same speed as the output shaft 19.The ring gear member 234 rotates at the same speed as the input shaft17. The planet carrier assembly member 236, and therefore the outputshaft 19, rotates at a speed determined from the speed of the ring gearmember 234 and the ring gear/sun gear tooth ratio of the planetary gearset 230. The numerical value of the fourth forward speed ratio isdetermined utilizing the ring gear/sun gear tooth ratio of the planetarygear set 230.

The fifth forward speed ratio is established with the engagement of theinput clutch 262, the braking synchronizer 265 and the synchronizers266, 270. The input clutch 262 and the synchronizer 266 connect theplanet carrier assembly member 226 to the input shaft 17. The brakingsynchronizer 265 connects the ring gear member 224 to the transmissionhousing 280. The synchronizer 270 connects the sun gear member 222 tothe planet carrier assembly member 236. The sun gear member 222 and theplanet carrier assembly member 236 rotate at the same speed as theoutput shaft 19. The planet carrier assembly member 226 rotates at thesame speed as the input shaft 17. The ring gear member 224 does notrotate. The sun gear member 222, and therefore the output shaft 19,rotates at a speed determined from the speed of the planet carrierassembly member 226 and the ring gear/sun gear tooth ratio of theplanetary gear set 220. The numerical value of the fifth forward speedratio is determined utilizing the ring gear/sun gear tooth ratio of theplanetary gear set 220.

The sixth forward speed ratio is established with the engagement of theinput clutch 263, the braking synchronizer 271 and the synchronizer 274.The input clutch 263 connects the ring gear member 234 to the inputshaft 17. The braking synchronizer 271 connects the ring gear member 244to the transmission housing 280. The synchronizer 274 connects theplanet carrier assembly member 236 to the sun gear member 242. The sungear member 232 rotates at the same speed as the planet carrier assemblymember 246. The planet carrier assembly member 236 and the sun gearmember 242 rotate at the same speed as the output shaft 19. The ringgear member 234 rotates at the same speed as the input shaft 17. Theplanet carrier assembly member 236, and therefore the output shaft 19,rotates at a speed determined from the speed of the ring gear member234, the speed of the sun gear member 232 and the ring gear/sun geartooth ratio of the planetary gear set 230. The ring gear member 244 doesnot rotate. The planet carrier assembly member 246 rotates at a speeddetermined from the speed of the sun gear member 242 and the ringgear/sun gear tooth ratio of the planetary gear set 240. The numericalvalue of the sixth forward speed ratio is determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 230, 240.

As previously set forth, the truth table of FIG. 3 b describes thecombinations of engagements utilized for six forward speed ratios andone reverse speed ratio. The truth table also provides an example ofspeed ratios that are available with the family member described above.These examples of speed ratios are determined the tooth ratios given inFIG. 3 b. The R1/S1 value is the tooth ratio of the planetary gear set220; the R2/S2 value is the tooth ratio of the planetary gear set 230;and the R3/S3 value is the tooth ratio of the planetary gear set 240.Also depicted in FIG. 3 b is a chart representing the ratio stepsbetween adjacent forward speed ratios and the reverse speed ratio. Forexample, the first to second ratio interchange has a step of 1.85.

A powertrain 310, shown in FIG. 4 a, includes the engine 12, a planetarytransmission 314, and the final drive mechanism 16. The planetarytransmission 314 includes an input shaft 17 continuously connected withthe engine 12, a planetary gear arrangement 318, and an output shaft 19continuously connected with the final drive mechanism 16. The planetarygear arrangement 318 includes three planetary gear sets 320, 330 and340.

The planetary gear set 320 includes a sun gear member 322, a ring gearmember 324, and a planet carrier assembly member 326. The planet carrierassembly member 326 includes a plurality of intermeshing pinion gears327, 328 rotatably mounted on a carrier member 329 and disposed inmeshing relationship with the ring gear member 324 and the sun gearmember 322, respectively.

The planetary gear set 330 includes a sun gear member 332, a ring gearmember 334, and a planet carrier assembly member 336. The planet carrierassembly member 336 includes a plurality of intermeshing pinion gears337, 338 rotatably mounted on a carrier member 339 and disposed inmeshing relationship with the ring gear member 334 and the sun gearmember 332, respectively.

The planetary gear set 340 includes a sun gear member 342, a ring gearmember 344, and a planet carrier assembly member 346. The planet carrierassembly member 346 includes a plurality of pinion gears 347 rotatablymounted on a carrier member 349 and disposed in meshing relationshipwith both the sun gear member 342 and the ring gear member 344.

As a result of the dual clutch arrangement of the invention, the threeplanetary gear sets 320, 330 and 340 are divided into first and secondtransmission subsets 360, 361 which are alternatively engaged to provideodd number and even number speed ranges, respectively. Transmissionsubset 360 includes planetary gear set 320, and transmission subset 361includes planetary gear sets 330 and 340. The output shaft 19 iscontinuously connected with a member of transmission subset 361.

As mentioned above, the first and second input clutches 362, 363 arealternatively engaged for transmitting power from the input shaft 17 totransmission subset 360 or transmission subset 361. The first and secondinput clutches 362, 363 are controlled electronically, and thedisengaged input clutch is gradually engaged while the engaged inputclutch is gradually disengaged to facilitate transfer of power from onetransmission subset to another. In this manner, shift quality ismaintained, as in an automatic transmission, while providing better fueleconomy because no torque converter is required, and hydraulicsassociated with “wet” clutching are eliminated. All gear speeds arepreselected within the transmission subsets 360, 361 prior to engagingthe respective input clutches 362, 363. The preselection is achieved bymeans of electronically controlled synchronizers. As shown, theplanetary gear arrangement includes eleven torque transmittingmechanisms 364, 365, 366, 367, 368, 369, 370, 371, 372, 373 and 374. Thetorque transmitting mechanisms 364, 365, 371 and 372 comprise brakingsynchronizers (brakes) which connect gears to the transmission housing380, and the torque transmitting mechanisms 366, 367, 368, 369, 370, 373and 374 comprise rotating synchronizers.

Accordingly, the input shaft 17 is alternately connected with the firstand second transmission subsets 360, 361 (i.e. through the clutch 362 tothe synchronizers 366 and 367 and through the clutch 363 to the ringgear member 334). The sun gear member 332 is continuously connected withthe sun gear member 342 through the interconnecting member 376.

The planet carrier assembly member 326 is selectively connectable withthe transmission housing 380 through the braking synchronizer 364. Thesun gear member 322 is selectively connectable with the transmissionhousing 380 through the braking synchronizer 365. The planet carrierassembly member 326 is selectively connectable with the input shaft 17through the input clutch 362 and the synchronizer 366. The ring gearmember 324 is selectively connectable with the input shaft 17 throughthe input clutch 362 and the synchronizer 367. The sun gear member 322is selectively connectable with the planet carrier assembly member 336through the synchronizer 368. The planet carrier assembly member 326 isselectively connectable with the planet carrier assembly member 336through the synchronizer 369. The ring gear member 324 is selectivelyconnectable with the planet carrier assembly member 336 through thesynchronizer 370. The ring gear member 344 is selectively connectablewith the transmission housing 380 through the braking synchronizer 371.The planet carrier assembly member 346 is selectively connectable withthe transmission housing 380 through the braking synchronizer 372. Theplanet carrier assembly member 336 is selectively connectable with thering gear member 344 through the synchronizer 373. The planet carrierassembly member 336 is selectively connectable with the planet carrierassembly member 346 through the synchronizer 374.

The truth tables given in FIGS. 4 b, 5 b, 6 b, 7 b, 8 b, 9 b, 10 b, 11 band 12 b show the engagement sequences for the torque transmittingmechanisms to provide at least five forward speed ratios and one reversespeed ratio. As shown and described above for the configurations inFIGS. 1 a, 2 a and 3 a, those skilled in the art will understand fromthe respective truth tables how the speed ratios are established throughthe planetary gear sets identified in the written description.

The truth table shown in FIG. 4 b describes the engagement combinationand engagement sequence necessary to provide the reverse drive ratio andsix forward speed ratios. A sample of the numerical values for theratios is also provided in the truth table of FIG. 4 b. These values aredetermined utilizing the ring gear/sun gear tooth ratios also given inFIG. 4 b. The R1/S1 value is the tooth ratio for the planetary gear set320; the R2/S2 value is the tooth ratio for the planetary gear set 330;and the R3/S3 value is the tooth ratio for the planetary gear set 340.Also given in FIG. 4 b is a chart describing the step ratios between theadjacent forward speed ratios and the reverse to first forward speedratio. For example, the first to second forward speed ratio step is1.76.

Those skilled in the art will recognize that the numerical values of thereverse and first forward speed ratios are determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 330, 340. Thenumerical values of the second, fourth and sixth forward speed ratiosare determined utilizing the ring gear/sun gear tooth ratio of theplanetary gear set 320. The numerical value of the third forward speedratio is 1. The numerical value of the fifth forward speed ratio isdetermined utilizing the ring gear/sun gear tooth ratio of the planetarygear set 330.

A powertrain 410 shown in FIG. 5 a includes a conventional engine 12, aplanetary transmission 414, and a conventional final drive mechanism 16.The planetary transmission 414 includes an input shaft 17 connected withthe engine 12, a planetary gear arrangement 418, and an output shaft 19continuously connected with the final drive mechanism 16. The planetarygear arrangement 418 includes three planetary gear sets 420, 430 and440.

The planetary gear set 420 includes a sun gear member 422, a ring gearmember 424, and a planet carrier assembly member 426. The planet carrierassembly member 426 includes a plurality of intermeshing pinion gears427, 428 rotatably mounted on a carrier member 429 and disposed inmeshing relationship with the ring gear member 424 and the sun gearmember 422, respectively.

The planetary gear set 430 includes a sun gear member 432, a ring gearmember 434, and a planet carrier assembly member 436. The planet carrierassembly member 436 includes a plurality of intermeshing pinion gears437, 438 rotatably mounted on a carrier member 439 and disposed inmeshing relationship with the ring gear member 434 and the sun gearmember 432, respectively.

The planetary gear set 440 includes a sun gear member 442, a ring gearmember 444, and a planet carrier assembly member 446. The planet carrierassembly member 446 includes a plurality of intermeshing pinion gears447, 448 rotatably mounted on a carrier member 449 and disposed inmeshing relationship with the ring gear member 444 and the sun gearmember 442, respectively.

As a result of the dual clutch arrangement of the invention, the threeplanetary gear sets 420, 430 and 440 are divided into first and secondtransmission subsets 460, 461 which are alternatively engaged to provideodd number and even number speed ranges, respectively. Transmissionsubset 460 includes planetary gear set 420, and transmission subset 461includes planetary gear sets 430 and 440. The output shaft 19 iscontinuously connected with a member of transmission subset 461.

As mentioned above, the first and second input clutches 462, 463 arealternatively engaged for transmitting power from the input shaft 17 totransmission subset 460 or transmission subset 461. The first and secondinput clutches 462, 463 are controlled electronically, and thedisengaged input clutch is gradually engaged while the engaged inputclutch is gradually disengaged to facilitate transfer of power from onetransmission subset to another. In this manner, shift quality ismaintained, as in an automatic transmission, while providing better fueleconomy because no torque converter is required, and hydraulicsassociated with “wet” clutching are eliminated. All gear speeds arepreselected within the transmission subsets 460, 461 prior to engagingthe respective input clutches 462, 463. The preselection is achieved bymeans of electronically controlled synchronizers. As shown, theplanetary gear arrangement includes eleven torque transmittingmechanisms 464, 465, 466, 467, 468, 469, 470, 471, 472, 473 and 474. Thetorque transmitting mechanisms 464, 465, 471 and 472 comprise brakingsynchronizers (brakes) which connect gears to the transmission housing480, and the torque transmitting mechanisms 466, 467, 468, 469, 470, 473and 474 comprise rotating synchronizers.

Accordingly, the input shaft 17 is alternately connected with the firstand second transmission subsets 460, 461 (i.e. through the clutch 462 tothe synchronizers 466 and 467 and through the clutch 463 to the ringgear member 434). The sun gear member 432 is continuously connected withthe planet carrier assembly member 446 through the interconnectingmember 476.

The planet carrier assembly member 426 is selectively connectable withthe transmission housing 480 through the braking synchronizer 464. Thesun gear member 422 is selectively connectable with the transmissionhousing 480 through the braking synchronizer 465. The planet carrierassembly member 426 is selectively connectable with the input shaft 17through the input clutch 462 and the synchronizer 466. The ring gearmember 424 is selectively connectable with the input shaft 17 throughthe input clutch 462 and the synchronizer 467. The sun gear member 422is selectively connectable with the planet carrier assembly member 436through the synchronizer 468. The planet carrier assembly member 426 isselectively connectable with the planet carrier assembly member 436through the synchronizer 469. The ring gear member 424 is selectivelyconnectable with the planet carrier assembly member 436 through thesynchronizer 470. The ring gear member 444 is selectively connectablewith the transmission housing 480 through the braking synchronizer 471.The sun gear member 442 is selectively connectable with the transmissionhousing 480 through the braking synchronizer 472. The planet carrierassembly member 436 is selectively connectable with the ring gear member444 through the synchronizer 473. The planet carrier assembly member 436is selectively connectable with the sun gear member 442 through thesynchronizer 474.

As shown in FIG. 5 b, and in particular the truth table disclosedtherein, the input clutches and torque transmitting mechanisms areselectively engaged in combinations of at least three to provide sixforward speed ratios and a reverse speed ratio.

FIG. 5 b also provides a chart of the ratio steps between adjacentforward ratios and between the reverse and first ratio. For example, theratio step between the first and second forward ratios is 1.41. Thoseskilled in the art will recognize that the numerical values of thereverse and first forward speed ratios are determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 430, 440. Thenumerical values of the second, fourth and sixth forward speed ratiosare determined utilizing the ring gear/sun gear tooth ratio of theplanetary gear set 420. The numerical value of the third forward speedratio is 1. The numerical value of the fifth forward speed ratio isdetermined utilizing the ring gear/sun gear tooth ratio of the planetarygear set 430.

A powertrain 510, shown in FIG. 6 a, includes a conventional engine 12,a powertrain 514, and a conventional final drive mechanism 16. Thepowertrain 514 includes an input shaft 17 connected with the engine 12,a planetary gear arrangement 518, and an output shaft 19 continuouslyconnected with the final drive mechanism 16. The planetary geararrangement 518 includes three planetary gear sets 520, 530 and 540.

The planetary gear set 520 includes a sun gear member 522, a ring gearmember 524, and a planet carrier assembly member 526. The planet carrierassembly member 526 includes a plurality of pinion gears 527 rotatablymounted on a carrier member 529 and disposed in meshing relationshipwith both the sun gear member 522 and the ring gear member 524.

The planetary gear set 530 includes a sun gear member 532, a ring gearmember 534, and a planet carrier assembly member 536. The planet carrierassembly member 536 includes a plurality of pinion gears 537 rotatablymounted on a carrier member 539 and disposed in meshing relationshipwith both the sun gear member 532 and the ring gear member 534.

The planetary gear set 540 includes a sun gear member 542, a ring gearmember 544, and a planet carrier assembly member 546. The planet carrierassembly member 546 includes a plurality of intermeshing pinion gears547, 548 rotatably mounted on a carrier member 549 and disposed inmeshing relationship with the ring gear member 544 and the sun gearmember 542, respectively.

As a result of the dual clutch arrangement of the invention, the threeplanetary gear sets 520, 530 and 540 are divided into first and secondtransmission subsets 560, 561 which are alternatively engaged to provideodd number and even number speed ranges, respectively. Transmissionsubset 560 includes planetary gear set 520, and transmission subset 561includes planetary gear sets 530 and 540. The output shaft 19 iscontinuously connected with a member of transmission subset 561.

In this family member, which is a derivative of the family member shownin FIG. 1 a, rather than having two input clutches and elevensynchronizers, three input clutch clutches and nine synchronizers areutilized to achieve reduced content. The first input clutch and firstand second synchronizers in FIG. 1 a are here operatively replaced by afirst and second input clutch 566 and 567, and the second input clutchin FIG. 1 a remains here as a third input clutch 563. The input clutches563, 566 and 567 are controlled electronically, and the disengaged inputclutch is gradually engaged while the engaged input clutch is graduallydisengaged to facilitate transfer of power from one transmission subsetto another. In this manner, shift quality is maintained, as in anautomatic transmission, while providing better fuel economy because notorque converter is required, and hydraulics associated with “wet”clutching are eliminated. All gear speeds are preselected within thetransmission subsets 560, 561 prior to engaging the respective inputclutch 563, 566, or 567. The preselection is achieved by means ofelectronically controlled synchronizers. As shown, the planetary geararrangement includes nine torque transmitting mechanisms 564, 565, 568,569, 570, 571, 572, 573 and 574. The torque transmitting mechanisms 564,565, 571 and 572 comprise braking synchronizers (brakes) which connectgears to the transmission housing 580, and the torque transmittingmechanisms 568, 569, 570, 573 and 574 comprise rotating synchronizers.

Accordingly, the input shaft 17 is alternately connected with the firstand second transmission subsets 560, 561 (i.e. through the clutch 566 tothe planet carrier assembly member 526, through the clutch 567 to thesun gear member 522 and through the clutch 563 to the sun gear member532). The planet carrier assembly member 536 is continuously connectedwith the ring gear member 544 through the interconnecting member 576.

The planet carrier assembly member 526 is selectively connectable withthe transmission housing 580 through the braking synchronizer 564. Thering gear member 524 is selectively connectable with the transmissionhousing 580 through the braking synchronizer 565. The planet carrierassembly member 526 is selectively connectable with the input shaft 17through the input clutch 566. The sun gear member 522 is selectivelyconnectable with the input shaft 17 through the input clutch 567. Thesun gear member 532 is selectively connectable with the input shaft 17through the input clutch 563. The ring gear member 524 is selectivelyconnectable with the planet carrier assembly member 536 through thesynchronizer 568. The planet carrier assembly member 526 is selectivelyconnectable with the planet carrier assembly member 536 through thesynchronizer 569. The sun gear member 524 is selectively connectablewith the planet carrier assembly member 536 through the synchronizer570. The planet carrier assembly member 546 is selectively connectablewith the transmission housing 580 through the braking synchronizer 571.The sun gear member 542 is selectively connectable with the transmissionhousing 580 through the braking synchronizer 572. The ring gear member534 is selectively connectable with the planet carrier assembly member546 through the synchronizer 573. The ring gear member 534 isselectively connectable with the sun gear member 542 through thesynchronizer 574.

As shown in FIG. 6 b, and in particular the truth table disclosedtherein, the input clutch and torque transmitting mechanisms areselectively engaged in combinations of three to provide six forwardspeed ratios and a reverse speed ratio. The chart of FIG. 6 b describesthe ratio steps between adjacent forward speed ratios and the ratio stepbetween the reverse and first forward speed ratio.

Those skilled in the art, upon reviewing the truth table and theschematic representation of FIG. 6 a can determine that the numericalvalues of the reverse, first and fifth forward speed ratios aredetermined utilizing the ring gear/sun gear tooth ratio of the planetarygear set 520. The numerical value of the second forward speed ratio isdetermined utilizing the ring gear/sun gear tooth ratio of the planetarygear set 530. The numerical value of the third forward speed ratio is 1.The numerical values of the fourth and sixth forward speed ratios aredetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 530, 540.

The sample speed ratios given in the truth table are determinedutilizing the tooth ratio values also given in FIG. 6 b. R1/S1 value isthe tooth ratio of the planetary gear set 520; the R2/S2 value is thetooth ratio of the planetary gear set 530; and the R3/S3 value is thetooth ratio of the planetary gear set 540.

A powertrain 610, shown in FIG. 7 a, has the engine and torque converter12, a planetary transmission 614, and the final drive mechanism 16. Theplanetary transmission 614 includes the input shaft 17, a planetary geararrangement 618, and the output shaft 19. The planetary gear arrangement618 includes three planetary gear sets 620, 630 and 640.

The planetary gear set 620 includes a sun gear member 622, a ring gearmember 624, and a planet carrier assembly member 626. The planet carrierassembly member 626 includes a plurality of pinion gears 627 rotatablymounted on a carrier member 629 and disposed in meshing relationshipwith both the sun gear member 622 and the ring gear member 624.

The planetary gear set 630 includes a sun gear member 632, a ring gearmember 634, and a planet carrier assembly member 636. The planet carrierassembly member 636 includes a plurality of intermeshing pinion gears637, 638 rotatably mounted on a carrier member 639 and disposed inmeshing relationship with the ring gear member 634 and the sun gearmember 632, respectively.

The planetary gear set 640 includes a sun gear member 642, a ring gearmember 644, and a planet carrier assembly member 646. The planet carrierassembly member 646 includes a plurality of intermeshing pinion gears647, 648 rotatably mounted on a carrier member 649 and disposed inmeshing relationship with the ring gear member 644 and the sun gearmember 642, respectively.

As a result of the dual clutch arrangement of the invention, the fourplanetary gear sets 620, 630, 640 and 650 are divided into first andsecond transmission subsets 660, 661 which are alternatively engaged toprovide odd number and even number speed ranges, respectively.Transmission subset 660 includes planetary gear set 620, andtransmission subset 661 includes planetary gear sets 630 and 640. Theoutput shaft 19 is continuously connected with a member of transmissionsubset 661.

In this family member, which is a derivative of the family member shownin FIG. 2 a, rather than having two input clutches and elevensynchronizers, three input clutches and nine synchronizer are utilizedto achieve reduced content. The first input clutch and first and secondsynchronizers in FIG. 2 a are here operatively replaced by a first and asecond input clutch 666 and 667, respectively; and the second inputclutch in FIG. 2 a remains here as a third input clutch 663. The inputclutches 663, 666 and 667 are controlled electronically, and thedisengaged input clutch is gradually engaged while the engaged inputclutch or synchronizer is gradually disengaged to facilitate transfer ofpower from one transmission subset to another. In this manner, shiftquality is maintained, as in an automatic transmission, while providingbetter fuel economy because no torque converter is required, andhydraulics associated with “wet” clutching are eliminated. All gearspeeds are preselected within the transmission subsets 660, 661 prior toengaging the respective input clutch 663, 666, or 667. The preselectionis achieved by means of electronically controlled synchronizers. Asshown, the planetary gear arrangement includes nine torque transmittingmechanisms 664, 665, 668, 669, 670, 671, 672, 673 and 674. The torquetransmitting mechanisms 664, 665, 671 and 672 comprise brakingsynchronizers (brakes) which connect gears to the transmission housing680, and the torque transmitting mechanisms 668, 669, 670, 673 and 674comprise rotating synchronizers.

Accordingly, the input shaft 17 is alternately connected with the firstand second transmission subsets 660, 661 (i.e. through the clutch 666 tothe planet carrier assembly member 626, through the clutch 667 to thesun gear member 622 and through the clutch 663 to the ring gear member634). The sun gear member 632 is continuously connected with the sungear member 642 through the interconnecting member 676.

The planet carrier assembly member 626 is selectively connectable withthe transmission housing 680 through the braking synchronizer 664. Thering gear member 624 is selectively connectable with the transmissionhousing 680 through the braking synchronizer 665. The planet carrierassembly member 626 is selectively connectable with the input shaft 17through the input clutch 666. The sun gear member 622 is selectivelyconnectable with the input shaft 17 through the input clutch 667. Thering gear member 634 is selectively connectable with the input shaft 17through the input clutch 663. The ring gear member 624 is selectivelyconnectable with the planet carrier assembly member 636 through thesynchronizer 668. The planet carrier assembly member 626 is selectivelyconnectable with the planet carrier assembly member 636 through thesynchronizer 669. The sun gear member 622 is selectively connectablewith the planet carrier assembly member 636 through the synchronizer670. The ring gear member 644 is selectively connectable with thetransmission housing 680 through the braking synchronizer 671. Theplanet carrier assembly member 646 is selectively connectable with thetransmission housing 680 through the braking synchronizer 672. Theplanet carrier assembly member 636 is selectively connectable with thering gear member 644 through the synchronizer 673. The planet carrierassembly member 636 is selectively connectable with the planet carrierassembly member 646 through the synchronizer 674.

As shown in FIG. 7 b, and in particular the truth table disclosedtherein, the input clutches and torque transmitting mechanisms areselectively engaged in combinations of three to provide six forwardspeed ratio and a reverse speed ratio. The ratio values given are by wayexample and are established utilizing the ring gear/sun gear toothratios given in FIG. 7 b. For example, the R1/S2 value is the toothratio of the planetary gear set 620; the R2/S2 value is the tooth ratioof the planetary gear set 630; and the R3/S3 value is the tooth ratio ofthe planetary gear set 640. The ratio steps between adjacent forwardratios and the reverse to first ratio are also given in FIG. 7 b.

Those skilled in the art will, upon reviewing the truth table of FIG. 7b, recognize that the numerical values of the reverse, first and fifthforward speed ratios are determined utilizing the ring gear/sun geartooth ratio of the planetary gear set 620. The numerical values of thesecond and sixth forward speed ratios are determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 630, 640. Thenumerical value of the third forward speed ratio is 1. The numericalvalue of the fourth forward speed ratio is determined utilizing the ringgear/sun gear tooth ratio of the planetary gear set 630.

A powertrain 710, shown in FIG. 8 a, has the conventional engine 12, aplanetary transmission 714, and the conventional final drive mechanism16. The engine 12 is continuously connected with the input shaft 17. Theplanetary transmission 714 is drivingly connected with the final drivemechanism 16 through the output shaft 19. The planetary transmission 714includes a planetary gear arrangement 718 that has a first planetarygear set 720, a second planetary gear set 730 and a third planetary gearset 740.

The planetary gear set 720 includes a sun gear member 722, a ring gearmember 724, and a planet carrier assembly member 726. The planet carrierassembly member 726 includes a plurality of pinion gears 727 rotatablymounted on a carrier member 729 and disposed in meshing relationshipwith both the sun gear member 722 and the ring gear member 724.

The planetary gear set 730 includes a sun gear member 732, a ring gearmember 734, and a planet carrier assembly member 736. The planet carrierassembly member 736 includes a plurality of intermeshing pinion gears737, 738 rotatably mounted on a carrier member 739 and disposed inmeshing relationship with the ring gear member 734 and the sun gearmember 732, respectively.

The planetary gear set 740 includes a sun gear member 742, a ring gearmember 744, and a planet carrier assembly member 746. The planet carrierassembly member 746 includes a plurality of intermeshing pinion gears747, 748 rotatably mounted on a carrier member 749 and disposed inmeshing relationship with the ring gear member 744 and the sun gearmember 742, respectively.

As a result of the dual clutch arrangement of the invention, the fourplanetary gear sets 720, 730, 740 and 750 are divided into first andsecond transmission subsets 760, 761 which are alternatively engaged toprovide odd number and even number speed ranges, respectively.Transmission subset 760 includes planetary gear set 720, andtransmission subset 761 includes planetary gear sets 730 and 740. Theoutput shaft 19 is continuously connected with a member of transmissionsubset 761.

In this family member, which is a derivative of the family member shownin FIG. 3 a, rather than having two input clutches and elevensynchronizers, three input clutches and nine synchronizers are utilizedto achieve reduced content. The first input clutch and first and secondsynchronizers in FIG. 3 a are here operatively replaced by a first andsecond input clutch 766 and 767, and the second input clutch in FIG. 3 aremains here as a third input clutch 763. The input clutches 763, 766and 767 are controlled electronically, and the disengaged input clutchis gradually engaged while the engaged input clutch is graduallydisengaged to facilitate transfer of power from one transmission subsetto another. In this manner, shift quality is maintained, as in anautomatic transmission, while providing better fuel economy because notorque converter is required, and hydraulics associated with “wet”clutching are eliminated. All gear speeds are preselected within thetransmission subsets 760, 761 prior to engaging the respective inputclutch 763, 766 or 767. The preselection is achieved by means ofelectronically controlled synchronizers. As shown, the planetary geararrangement includes nine torque transmitting mechanisms 764, 765, 768,769, 770, 771, 772, 773 and 774. The torque transmitting mechanisms 764,765, 771 and 772 comprise braking synchronizers (brakes) which connectgears to the transmission housing 780, and the torque transmittingmechanisms 768, 769, 770, 773 and 774 comprise rotating synchronizers.

Accordingly, the input shaft 17 is alternately connected with the firstand second transmission subsets 760, 761 (i.e. through the clutch 766 tothe planet carrier assembly member 726, through the clutch 767 to thesun gear member 722 and through the clutch 763 to the ring gear member734). The sun gear member 732 is continuously connected with the planetcarrier assembly member 746 through the interconnecting member 776.

The planet carrier assembly member 726 is selectively connectable withthe transmission housing 780 through the braking synchronizer 764. Thering gear member 724 is selectively connectable with the transmissionhousing 780 through the braking synchronizer 765. The planet carrierassembly member 726 is selectively connectable with the input shaft 17through the input clutch 766. The sun gear member 722 is selectivelyconnectable with the input shaft 17 through the input clutch 767. Thering gear member 734 is selectively connectable with the input shaft 17through the input clutch 763. The ring gear member 724 is selectivelyconnectable with the planet carrier assembly member 736 through thesynchronizer 768. The planet carrier assembly member 726 is selectivelyconnectable with the planet carrier assembly member 736 through thesynchronizer 769. The sun gear member 722 is selectively connectablewith the planet carrier assembly member 736 through the synchronizer770. The ring gear member 744 is selectively connectable with thetransmission housing 780 through the braking synchronizer 771. The sungear member 742 is selectively connectable with the transmission housing780 through the braking synchronizer 772. The planet carrier assemblymember 736 is selectively connectable with the ring gear member 744through the synchronizer 773. The planet carrier assembly member 736 isselectively connectable with the sun gear member 742 through thesynchronizer 774.

As shown in FIG. 8 b, and in particular the truth table disclosedtherein, the input clutches and torque transmitting mechanisms areselectively engaged in combinations of three to provide six forwardspeed ratios and a reverse speed ratio. Also given in the truth table isa set of numerical values that are attainable with the present inventionutilizing the ring gear/sun gear tooth ratios given in FIG. 8 b. TheR1/S1 value is the tooth ratio of the planetary gear set 720; the R2/S2value is the tooth ratio of the planetary gear set 730; and the R3/S3value is the tooth ratio of the planetary gear set 740.

FIG. 8 b also provides a chart of the ratio steps between adjacentforward ratios and between the reverse and first forward ratio. Forexample, the ratio step between the first and second forward ratios is1.85.

Those skilled will recognize that the numerical values of the reverse,first and fifth forward speed ratios are determined utilizing the ringgear/sun gear tooth ratio of the planetary gear set 720. The numericalvalues of the second and sixth forward speed ratios are determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear set730, 740. The numerical value of the third forward speed ratio is 1. Thenumerical value of the fourth forward speed ratio is determinedutilizing the ring gear/sun gear tooth ratio of the planetary gear set730.

A powertrain 810, shown in FIG. 9 a, has the conventional engine 12, aplanetary transmission 814, and the final drive mechanism 16. The engine12 is continuously connected with the input shaft 17. The planetarytransmission 814 is drivingly connected with final drive mechanism 16through output shaft 19. The planetary transmission 814 includes aplanetary gear arrangement 818 that has a first planetary gear set 820,a second planetary gear set 830 and a third planetary gear set 840.

The planetary gear set 820 includes a sun gear member 822, a ring gearmember 824, and a planet carrier assembly member 826. The planet carrierassembly member 826 includes a plurality of intermeshing pinion gears827, 828 rotatably mounted on a carrier member 829 and disposed inmeshing relationship with the ring gear member 824 and the sun gearmember 822, respectively.

The planetary gear set 830 includes a sun gear member 832, a ring gearmember 834, and a planet carrier assembly member 836. The planet carrierassembly member 836 includes a plurality of intermeshing pinion gears837, 838 rotatably mounted on a carrier member 839 and disposed inmeshing relationship with the ring gear member 834 and the sun gearmember 832, respectively.

The planetary gear set 840 includes a sun gear member 842, a ring gearmember 844, and a planet carrier assembly member 846. The planet carrierassembly member 846 includes a plurality of pinion gears 847 rotatablymounted on a carrier member 849 and disposed in meshing relationshipwith both the sun gear member 842 and the ring gear member 844.

As a result of the dual clutch arrangement of the invention, the fourplanetary gear sets 820, 830 and 840 are divided into first and secondtransmission subsets 860, 861 which are alternatively engaged to provideodd number and even number speed ranges, respectively. Transmissionsubset 860 includes planetary gear set 820, and transmission subset 861includes planetary gear sets 830 and 840. The output shaft 19 iscontinuously connected with a member of transmission subset 861.

In this family member, which is a derivative of the family member shownin FIG. 4 a, rather than having two input clutches and elevensynchronizers, three input clutches and nine synchronizers are utilizedto achieve reduced content. The first input clutch and first and secondsynchronizers in FIG. 4 a are here operatively replaced by a first andsecond input clutch 866 and 867, and the second input clutch in FIG. 4 aremains here as a third input clutch 863. The input clutches 863, 866and 867 are controlled electronically, and the disengaged input clutchis gradually engaged while the engaged input clutch is graduallydisengaged to facilitate transfer of power from one transmission subsetto another. In this manner, shift quality is maintained, as in anautomatic transmission, while providing better fuel economy because notorque converter is required, and hydraulics associated with “wet”clutching are eliminated. All gear speeds are preselected within thetransmission subsets 860, 861 prior to engaging the respective inputclutch 863, 866 or 867. The preselection is achieved by means ofelectronically controlled synchronizers. As shown, the planetary geararrangement includes nine torque transmitting mechanisms 864, 865, 868,869, 870, 871, 872, 873 and 874. The torque transmitting mechanisms 864,865, 871 and 872 comprise braking synchronizers (brakes) which connectgears to the transmission housing 880, and the torque transmittingmechanisms 868, 869, 870, 873 and 874 comprise rotating synchronizers.

Accordingly, the input shaft 17 is alternately connected with the firstand second transmission subsets 860, 861 (i.e. through the clutch 866 tothe planet carrier assembly member 826, through the clutch 867 to thering gear member 824, and through the clutch 863 to the ring gear member834). The sun gear member 832 is continuously connected with the sungear member 842 through the interconnecting member 876.

The planet carrier assembly member 826 is selectively connectable withthe transmission housing 880 through the braking synchronizer 864. Thesun gear member 822 is selectively connectable with the transmissionhousing 880 through the braking synchronizer 865. The planet carrierassembly member 826 is selectively connectable with the input shaft 17through the input clutch 866. The ring gear member 824 is selectivelyconnectable with the input shaft 17 through the input clutch 867. Thering gear member 834 is selectively connectable with the input shaft 17through the input clutch 863. The sun gear member 822 is selectivelyconnectable with the planet carrier assembly member 836 through thesynchronizer 868. The planet carrier assembly member 826 is selectivelyconnectable with the planet carrier assembly member 836 through thesynchronizer 869. The ring gear member 824 is selectively connectablewith the planet carrier assembly member 836 through the synchronizer870. The ring gear member 844 is selectively connectable with thetransmission housing 880 through the braking synchronizer 871. Theplanet carrier assembly member 846 is selectively connectable with thetransmission housing 880 through the braking synchronizer 872. Theplanet carrier assembly member 836 is selectively connectable with thering gear member 844 through the synchronizer 873. The planet carrierassembly member 836 is selectively connectable with the planet carrierassembly member 846 through the synchronizer 874.

As shown in FIG. 9 b, and in particular the truth table disclosedtherein, the input clutches and torque transmitting mechanisms areselectively engaged in combinations of three to provide six forwardspeed ratios and a reverse speed ratio. A sample of numerical values forthe individual ratios is also given in the truth table of FIG. 9 b.These numerical values have been calculated using the ring gear/sun geartooth ratios also given by way of example in FIG. 9 b. The R1/S1 valueis the tooth ratio of the planetary gear set 820; the R2/S2 value is thetooth ratio of planetary gear set 830; and the R3/S3 value is the toothratio of the planetary gear set 840. FIG. 9 b also describes the ratiosteps between adjacent forward ratios and between the reverse and firstforward ratio. For example, the ratio step between the first and secondforward ratios is 1.76.

Those skilled in the art of planetary transmissions will recognize thatthe numerical values of the reverse and first forward speed ratios aredetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 830, 840. The numerical values of the second, fourthand sixth forward speed ratios are determined utilizing the ringgear/sun gear tooth ratio of the planetary gear set 820. The numericalvalue of the third forward speed ratio is 1. The numerical value of thefifth forward speed ratio is determined utilizing the ring gear/sun geartooth ratio of the planetary gear set 830.

Referring to FIG. 10 a, a powertrain 910 is shown having a conventionalengine 12, a planetary transmission 914, and a conventional final drivemechanism 16. The planetary transmission 914 includes an input shaft 17connected with the engine 12, a planetary gear arrangement 918, and anoutput shaft 19 continuously connected with the final drive mechanism16. The planetary gear arrangement 918 includes three planetary gearsets 920, 930 and 940.

The planetary gear set 920 includes a sun gear member 922, a ring gearmember 924, and a planet carrier assembly member 926. The planet carrierassembly member 926 includes a plurality of intermeshing pinion gears927, 928 rotatably mounted on a carrier member 929 and disposed inmeshing relationship with the ring gear member 924 and the sun gearmember 922, respectively.

The planetary gear set 930 includes a sun gear member 932, a ring gearmember 934, and a planet carrier assembly member 936. The planet carrierassembly member 936 includes a plurality of intermeshing pinion gears937, 938 rotatably mounted on a carrier member 939 and disposed inmeshing relationship with the ring gear member 934 and the sun gearmember 932, respectively.

The planetary gear set 940 includes a sun gear member 942, a ring gearmember 944, and a planet carrier assembly member 946. The planet carrierassembly member 946 includes a plurality of intermeshing pinion gears947, 948 rotatably mounted on a carrier member 949 and disposed inmeshing relationship with the ring gear member 944 and the sun gearmember 942, respectively.

As a result of the dual clutch arrangement of the invention, the fourplanetary gear sets 920, 930, 940 and 950 are divided into first andsecond transmission subsets 960, 961 which are alternatively engaged toprovide odd number and even number speed ranges, respectively.Transmission subset 960 includes planetary gear set 920, andtransmission subset 961 includes planetary gear sets 930 and 940. Theoutput shaft 19 is continuously connected with a member of transmissionsubset 961.

In this family member, which is a derivative of the family member shownin FIG. 5 a, rather than having two input clutches and elevensynchronizers, three input clutches and nine synchronizer are utilizedto achieve reduced content. The first input clutch and first and secondsynchronizers in FIG. 5 a are here operatively replaced by a first andsecond input clutch 966 and 967; and the second input clutch in FIG. 5 aremains here as a third input clutch 963. The input clutches 963, 966and 967 are controlled electronically, and the disengaged input clutchor synchronizer is gradually engaged while the engaged input clutch orsynchronizer is gradually disengaged to facilitate transfer of powerfrom one transmission subset to another. In this manner, shift qualityis maintained, as in an automatic transmission, while providing betterfuel economy because no torque converter is required, and hydraulicsassociated with “wet” clutching are eliminated. All gear speeds arepreselected within the transmission subsets 960, 961 prior to engagingthe respective input clutch 963, 966 or 967. The preselection isachieved by means of electronically controlled synchronizers. As shown,the planetary gear arrangement includes eleven torque transmittingmechanisms 964, 965, 968, 969, 970, 971, 972, 973 and 974. The torquetransmitting mechanisms 964, 965, 971 and 972 comprise brakingsynchronizers (brakes) which connect gears to the transmission housing980, and the torque transmitting mechanisms 968, 969, 970, 973 and 974comprise rotating synchronizers.

Accordingly, the input shaft 17 is alternately connected with the firstand second transmission subsets 960, 961 (i.e. through the clutch 966 tothe planet carrier assembly member 926, through the clutch 967 to thering gear member 924, and through the clutch 963 to the ring gear member934). The sun gear member 932 is continuously connected with the planetcarrier assembly member 946 through the interconnecting member 976.

The planet carrier assembly member 926 is selectively connectable withthe transmission housing 980 through the braking synchronizer 964. Thesun gear member 922 is selectively connectable with the transmissionhousing 980 through the braking synchronizer 965. The planet carrierassembly member 926 is selectively connectable with the input shaft 17through the input clutch 966. The ring gear member 924 is selectivelyconnectable with the input shaft 17 through the input clutch 967. Thering gear member 934 is selectively connectable with the input shaft 17through the input clutch 963. The sun gear member 922 is selectivelyconnectable with the planet carrier assembly member 936 through thesynchronizer 968. The planet carrier assembly member 926 is selectivelyconnectable with the planet carrier assembly member 936 through thesynchronizer 969. The ring gear member 924 is selectively connectablewith the planet carrier assembly member 936 through the synchronizer970. The ring gear member 944 is selectively connectable with thetransmission housing 980 through the braking synchronizer 971. The sungear member 942 is selectively connectable with the transmission housing980 through the braking synchronizer 972. The planet carrier assemblymember 936 is selectively connectable with the ring gear member 944through the synchronizer 973. The planet carrier assembly member 936 isselectively connectable with the sun gear member 942 through thesynchronizer 974.

As shown in FIG. 10 b, and in particular the truth table disclosedtherein, the input clutches and torque transmitting mechanisms areselectively engaged in combinations of three to provide six forwardspeed ratio and a reverse speed ratio. The truth table also provides aset of examples for the numerical values for each of the reverse andforward speed ratios. These numerical values have been determinedutilizing the ring gear/sun gear tooth ratios given in FIG. 10 b. TheR1/S1 value is the tooth ratio of the planetary gear set 920; the R2/S2value is the tooth ratio of the planetary gear set 930; and the R3/S3value is the tooth ratio of the planetary gear set 940.

Those skilled in the art, upon reviewing the engagement combinations,will recognize that the numerical values of the reverse and firstforward speed ratios are determined utilizing the ring gear/sun geartooth ratios of the planetary gear sets 930, 940. The numerical valuesof the second, fourth and sixth forward speed ratios are determinedutilizing the ring gear/sun gear tooth ratio of the planetary gear set920. The numerical value of the third forward speed ratio is 1. Thenumerical value of the fifth forward speed ratio is determined utilizingthe ring gear/sun gear tooth ratio of the planetary gear set 930.

FIGS. 11 a and 11 b illustrate a transmission wherein one of the torquetransmitting mechanisms from a previously described configuration iseliminated to realize five forward speed ratios and a reverse speedratio. Specifically, the powertrain 1010, shown in FIG. 11 a isidentical to that shown in FIG. 1 a, except that the synchronizer 72 ofFIG. 1 a has been eliminated.

The powertrain 1010, shown in FIG. 11 a, includes the conventionalengine 12, a planetary transmission 1014, and the conventional finaldrive mechanism 16. The engine 12 is continuously connected with theinput shaft 17 of the planetary transmission 1014. The planetarytransmission is drivingly connected with the final drive mechanism 16.The planetary transmission 1014 includes a planetary gear arrangement1018 that has a first planetary gear set 1020, a second planetary gearset 1030 and a third planetary gear set 1040.

The planetary gear set 1020 includes a sun gear member 1022, a ring gearmember 1024, and a planet carrier assembly member 1026. The planetcarrier assembly member 1026 includes a plurality of pinion gears 1027rotatably mounted on a carrier member 1029 and disposed in meshingrelationship with both the sun gear member 1022 and the ring gear member1024.

The planetary gear set 1030 includes a sun gear member 1032, a ring gearmember 1034, and a planet carrier assembly member 1036. The planetcarrier assembly member 1036 includes a plurality of pinion gears 1037rotatably mounted on a carrier member 1039 and disposed in meshingrelationship with both the sun gear member 1032 and the ring gear member1034.

The planetary gear set 1040 includes a sun gear member 1042, a ring gearmember 1044, and a planet carrier assembly member 1046. The planetcarrier assembly member 1046 includes a plurality of intermeshing piniongears 1047, 1048 rotatably mounted on a carrier member 1049 and disposedin meshing relationship with the ring gear member 1044 and the sun gearmember 1042, respectively.

As a result of the dual clutch arrangement of the invention, the threeplanetary gear sets 1020, 1030 and 1040 are divided into first andsecond transmission subsets 1060, 1061 which are alternatively engagedto provide odd number and even number speed ranges, respectively.Transmission subset 1060 includes planetary gear set 1020, andtransmission subset 1061 includes planetary gear sets 1030 and 1040. Theoutput shaft 19 is continuously connected with a member of transmissionsubset 1061.

As mentioned above, the first and second input clutches 1062, 1063 arealternatively engaged for transmitting power from the input shaft 17 totransmission subset 1060 or transmission subset 1061. The first andsecond input clutches 1062, 1063 are controlled electronically, and thedisengaged input clutch is gradually engaged while the engaged inputclutch is gradually disengaged to facilitate transfer of power from onetransmission subset to another. In this manner, shift quality ismaintained, as in an automatic transmission, while providing better fueleconomy because no torque converter is required, and hydraulicsassociated with “wet” clutching are eliminated. All gear speeds arepreselected within the transmission subsets 1060, 1061 prior to engagingthe respective input clutches 1062, 1063. The preselection is achievedby means of electronically controlled synchronizers. As shown, theplanetary gear arrangement includes ten torque transmitting mechanisms1064,1065, 1066, 1067, 1068, 1069, 1070, 1071, 1073 and 1074. The torquetransmitting mechanisms 1064, 1065 and 1071 comprise brakingsynchronizers (brakes) which connect gears to the transmission housing1080, and the torque transmitting mechanisms 1066, 1067, 1068, 1069,1070, 1073 and 1074 comprise rotating synchronizers.

Accordingly, the input shaft 17 is alternately connected with the firstand second transmission subsets 1060, 1061 (i.e. through the clutch 1062to the synchronizers 1066 and 1067, and through the clutch 1063 to thesun gear member 1032). The planet carrier assembly member 1036 iscontinuously connected with the ring gear member 1044 through theinterconnecting member 1076.

The planet carrier assembly member 1026 is selectively connectable withthe transmission housing 1080 through the braking synchronizer 1064. Thering gear member 1024 is selectively connectable with the transmissionhousing 1080 through the braking synchronizer 1065. The planet carrierassembly member 1026 is selectively connectable with the input shaft 17through the input clutch 1062 and the synchronizer 1066. The sun gearmember 1022 is selectively connectable with the input shaft 17 throughthe input clutch 1062 and the synchronizer 1067. The ring gear member1024 is selectively connectable with the planet carrier assembly member1036 through the synchronizer 1068. The planet carrier assembly member1026 is selectively connectable with the planet carrier assembly member1036 through the synchronizer 1069. The sun gear member 1022 isselectively connectable with the planet carrier assembly member 1036through the synchronizer 1070. The planet carrier assembly member 1046is selectively connectable with the transmission housing 1080 throughthe braking synchronizer 1071. The ring gear member 1034 is selectivelyconnectable with the planet carrier assembly member 1046 through thesynchronizer 1073. The ring gear member 1034 is selectively connectablewith the sun gear member 1042 through the synchronizer 1074.

As shown in FIG. 11 b, and in particular the truth table disclosedtherein, the input clutches and torque transmitting mechanisms areselectively engaged in combinations of at least three to provide fiveforward speed ratios and a reverse speed ratio. A sample of thenumerical values for the ratios is also provided in the truth table ofthe FIG. 11 b. These values are determined utilizing the ring gear/sungear tooth ratios also given in FIG. 11 b. The R1/S1 value is the toothratio of the planetary gear set 1020; the R2/S2 value is the tooth ratioof the planetary gear set 1030; and the R3/S3 value is the tooth ratioof the planetary gear set 1040. Also given in FIG. 11 b is a chartdescribing the step ratios between the adjacent forward speed ratios andthe reverse to first forward speed ratio.

Those skilled in the art will recognize that the numerical values of thereverse, first and fifth forward speed ratios are determined utilizingthe ring gear/sun gear tooth ratio of the planetary gear set 1020. Thenumerical value of the second forward speed ratio is determinedutilizing the ring gear/sun gear tooth ratio of the planetary gear set1030. The numerical value of the third forward speed ratio is 1 . Thenumerical value of the fourth forward speed ratio is determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets1030, 1040.

FIGS. 12 a and 12 b illustrate a transmission wherein two of the torquetransmitting mechanisms from a previously described configuration areeliminated to realize five forward speed ratios and a reverse speedratio. Specifically, the powertrain 1110, shown in FIG. 11 a isidentical to that shown in FIG. 4 a, except that the synchronizers 364and 368 of FIG. 4 a have been eliminated.

The powertrain 1110, shown in FIG. 12 a, includes the conventionalengine 12, a planetary transmission 1114, and the conventional finaldrive mechanism 16. The engine 12 is continuously connected with theinput shaft 17 of the planetary transmission 1114. The planetarytransmission is drivingly connected with the final drive mechanism 16.The planetary transmission 1114 includes a planetary gear arrangement1118 that has a first planetary gear set 1120, a second planetary gearset 1130 and a third planetary gear set 1140.

The planetary gear set 1120 includes a sun gear member 1122, a ring gearmember 1124, and a planet carrier assembly member 1126. The planetcarrier assembly member 1126 includes a plurality of intermeshing piniongears 1127, 1128 rotatably mounted on a carrier member 1129 and disposedin meshing relationship with the ring gear member 1124 and the sun gearmember 1122, respectively.

The planetary gear set 1130 includes a sun gear member 1132, a ring gearmember 1134, and a planet carrier assembly member 1136. The planetcarrier assembly member 1136 includes a plurality of intermeshing piniongears 1137, 1138 rotatably mounted on a carrier member 1139 and disposedin meshing relationship with the ring gear member 1134 and the sun gearmember 1132, respectively.

The planetary gear set 1140 includes a sun gear member 1142, a ring gearmember 1144, and a planet carrier assembly member 1146. The planetcarrier assembly member 1146 includes a plurality of pinion gears 1147rotatably mounted on a carrier member 1149 and disposed in meshingrelationship with both the sun gear member 1142 and the ring gear member1144.

As a result of the dual clutch arrangement of the invention, the threeplanetary gear sets 1120, 1130 and 1140 are divided into first andsecond transmission subsets 1160, 1161 which are alternatively engagedto provide odd number and even number speed ranges, respectively.Transmission subset 1160 includes planetary gear set 1120, andtransmission subset 1161 includes planetary gear sets 1130 and 1140. Theoutput shaft 19 is continuously connected with a member of transmissionsubset 1161.

As mentioned above, the first and second input clutches 1162, 1163 arealternatively engaged for transmitting power from the input shaft 17 totransmission subset 1160 or transmission subset 1161. The first andsecond input clutches 1162, 1163 are controlled electronically, and thedisengaged input clutch is gradually engaged while the engaged inputclutch is gradually disengaged to facilitate transfer of power from onetransmission subset to another. In this manner, shift quality ismaintained, as in an automatic transmission, while providing better fueleconomy because no torque converter is required, and hydraulicsassociated with “wet” clutching are eliminated. All gear speeds arepreselected within the transmission subsets 1160, 1161 prior to engagingthe respective input clutches 1162, 1163. The preselection is achievedby means of electronically controlled synchronizers. As shown, theplanetary gear arrangement includes nine torque transmitting mechanisms1165, 1166, 1167, 1169, 1170, 1171, 1172, 1173 and 1174. The torquetransmitting mechanisms 1165, 1171 and 1172 comprise brakingsynchronizers (brakes) which connect gears to the transmission housing1180, and the torque transmitting mechanisms 1166, 1167, 1169, 1170,1173 and 1174 comprise rotating synchronizers.

Accordingly, the input shaft 17 is alternately connected with the firstand second transmission subsets 1160, 1161 (i.e. through the clutch 1162to the synchronizers 1166 and 1167, and through the clutch 1163 to thering gear member 1134). The sun gear member 1132 is continuouslyconnected with the sun gear member 1142 through the interconnectingmember 1176.

The sun gear member 1122 is selectively connectable with thetransmission housing 1180 through the braking synchronizer 1165. Theplanet carrier assembly member 1126 is selectively connectable with theinput shaft 17 through the input clutch 1162 and the synchronizer 1166.The ring gear member 1124 is selectively connectable with the inputshaft 17 through the input clutch 1162 and the synchronizer 1167. Theplanet carrier assembly member 1126 is selectively connectable with theplanet carrier assembly member 1136 through the synchronizer 1169. Thering gear member 1124 is selectively connectable with the planet carrierassembly member 1136 through the synchronizer 1170. The ring gear member1144 is selectively connectable with the transmission housing 1180through the braking synchronizer 1171. The planet carrier assemblymember 1146 is selectively connectable with the transmission housing1180 through the braking synchronizer 1172. The planet carrier assemblymember 1136 is selectively connectable with the ring gear member 1144through the synchronizer 1173. The planet carrier assembly member 1136is selectively connectable with the planet carrier assembly member 1146through the synchronizer 1174.

As shown in FIG. 12 b, and in particular the truth table disclosedtherein, the input clutches and torque transmitting mechanisms areselectively engaged in combinations of at least three to provide fiveforward speed ratios and a reverse speed ratio. A sample of thenumerical values for the ratios is also provided in the truth table ofthe FIG. 12 b. These values are determined utilizing the ring gear/sungear tooth ratios also given in FIG. 12 b. The R1/S1 value is the toothratio of the planetary gear set 1120; the R2/S2 value is the tooth ratioof the planetary gear set 1130; and the R3/S3 value is the tooth ratioof the planetary gear set 1140. Also given in FIG. 12 b is a chartdescribing the step ratios between the adjacent forward speed ratios andthe reverse to first forward speed ratio.

Those skilled in the art will recognize that the numerical values of thereverse and first forward speed ratio are determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 1130, 1140. Thenumerical values of the second and fourth forward speed ratios aredetermined utilizing the ring gear/sun gear tooth ratio of the planetarygear set 1120. The numerical value of the third forward speed ratiois 1. The numerical value of the fifth forward speed ratio is determinedutilizing the ring gear/sun gear tooth ratio of the planetary gear set1130.

While the best modes for carrying out the invention have been describedin detail, those familiar with the art to which this invention relateswill recognize various alternative designs and embodiments forpracticing the invention within the scope of the appended claims.

1. A multi-speed transmission comprising: an input shaft; an outputshaft; a stationary member; first, second and third planetary gear setseach having first, second and third members; a first and second inputclutch connected with said input shaft; said second member of saidsecond planetary gear set being continuously connected with said secondinput clutch; a first interconnecting member continuouslyinterconnecting a member of said second planetary gear set with a memberof said third planetary gear set; and nine torque-transmittingmechanisms for selectively interconnecting said members of said first,second or third planetary gear sets with said first or second inputclutch, said output shaft, said interconnecting member, said stationarymember or with other members of said planetary gear sets, two of saidnine torque-transmitting mechanisms being selectively operable forinterconnecting said first and second members of said first planetarygear set with the first member of said second planetary gear set andsaid output shaft, said nine torque-transmitting mechanisms beingengaged in combinations of at least three to establish at least fiveforward speed ratios and a reverse speed ratio between said input shaftand said output shaft.
 2. The transmission defined in claim 1, whereinthe first and second of said nine torque-transmitting mechanisms areselectively operable for interconnecting the first member and the secondmember of said first planetary gear set, respectively, with said firstinput clutch.
 3. The transmission defined in claim 1, wherein the fifthand sixth of said nine torque-transmitting mechanisms are selectivelyoperable for interconnecting members of said second planetary gear setwith members of said third planetary gear set.
 4. The transmissiondefined in claim 1, wherein the seventh of said nine torque-transmittingmechanisms is selectively operable for interconnecting a member of saidfirst planetary gear set with said stationary member.
 5. Thetransmission defined in claim 1, wherein the eighth and ninth of saidnine torque-transmitting mechanisms is selectively operable forinterconnecting members of said third planetary gear set with saidstationary member.
 6. The transmission as defined in claim 1, furthercomprising a tenth torque-transmitting mechanism, wherein three of saidten torque-transmitting mechanisms are selectively operable forinterconnecting said first, second and third members of said firstplanetary gear set with the first member of said second planetary gearset and said output shaft.
 7. The transmission defined in claim 6,wherein the first and second of said ten torque-transmitting mechanismsare selectively operable for interconnecting the first member and thesecond member of said first planetary gear set, respectively, with saidfirst input clutch.
 8. The transmission defined in claim 6, wherein thesixth and seventh of said ten torque-transmitting mechanisms areselectively operable for interconnecting members of said secondplanetary gear set with members of said third planetary gear set.
 9. Thetransmission defined in claim 6, wherein the eighth and ninth of saidten torque-transmitting mechanisms are selectively operable forinterconnecting members of said first planetary gear set with saidstationary member.
 10. The transmission defined in claim 6, wherein thetenth of said ten torque-transmitting mechanisms is selectively operablefor interconnecting a member of said third planetary gear set with saidstationary member.
 11. The transmission defined in claim 6, wherein saidfirst, second and third members of said planetary gear sets comprise asun gear member, a ring gear member and a planet carrier assemblymember, and wherein the planet carrier assembly members of a pluralityof said planetary gear sets are of the single pinion carriers.
 12. Thetransmission defined in claim 6, wherein said first, second and thirdmembers of said planetary gear sets comprise a sun gear member, a ringgear member and a planet carrier assembly member, and wherein the planetcarrier assembly members of a plurality of said planetary gear sets areof the double pinion carriers.
 13. The transmission defined in claim 6,wherein each of said ten torque-transmitting mechanisms comprises asynchronizer.
 14. The transmission defined in claim 6, wherein saidfirst input clutch is applied for odd number speed ranges and saidsecond input clutch is applied for even number speed ranges.
 15. Thetransmission defined in claim 6, wherein said first input clutch isapplied for even number speed ranges and said second input clutch isapplied for odd number speed ranges.
 16. The transmission defined inclaim 6, wherein selected ones of said ten torque-transmittingmechanisms are engaged prior to gear shifting to achieve shiftingwithout torque interruptions.